Explain Django caching strategies and implementation.

Caching improves performance by storing computed data. Types: • Per-site cache - entire site • Per-view cache - @cache_page decorator • Template fragment cache - {% cache %} • Low-level cache API Backends: • Database • File system • Memcached • Redis Features: • Cache keys, timeouts, versioning • Cache invalidation strategies Example: from django.core.cache import cache cache.set('key', 'value', 300)